The Minor iv Chord
One of the most common borrowed chords you will encounter is the minor iv chord. In major keys moving from the IV chord back to I is happens frequently. The minor iv chord, borrowed from the parallel minor key, often connects the IV and I chords of the major key. It shows up in other ways, too.
Example Minor iv Progression
For example, in the key of C major you may encounter this progression: C – F – Fm – C. C and F are the I and IV chord major triads from the key of C major. The Fm chord is “borrowed” from the parallel minor key of C minor.
The Minor iv Is Everywhere
This sound and progression is very common in most styles of music. It's extremely common in pop songs—especially ballads. The minor iv chord is also in countless jazz songs and standards. It is commonly found in one of the most common jazz song forms called 'Rhythm Changes' derived from George Gershwin's tune I Got Rhythm.
The IV to minor iv progression is one of the easier ones to identify. If you see a major chord followed by a minor chord with the same root (F - Fm), ask yourself are those chords built on the fourth of the key? Often it will be.
As you learn your diatonic chords in each key and recognize the common IV chord, the minor iv will jump out at you.
Once you have heard this sound a few times, you will start to notice this harmonic trick everywhere. Be sure to check out this lesson's suggested songs.
How Does the Minor iv Work?
The minor iv chord works so well because of the chromatic movement between the chord tones. Namely, the third of the IV chord moves down a half-step to the third of the minor iv chord which moves down to the fifth of the I chord.
So, in the progression of F (IV) – Fm (minor iv) – C (I) the connecting tones move A (3rd of F) to A♭ (3rd of Fm) to G (5th of C).
Basslines and the Minor iv
As a bass player, this progression is important to recognize and learn how to address. There are two main choices you can make when creating a bassline to this progression.
The first is both easy and, often, a good choice: play the root for both chords. In the key of C, play F for the F chord and F for the Fm chord. With this choice, you let the other instruments or melody highlight the change of the chords from major to minor while the bass note remains static. This can really add to the dramatic effect of this chord change. The listener hears the unchanging bass note—the point of reference—but hears the descending notes above it.
The second option is to emphasize or highlight the changing chord tones in your bassline. You can make those notes pop out. In the key of C, maybe you emphasize the A of the F chord and the A♭ of the Fm chord. Maybe the other instruments aren't playing the 3rds of the chords and you create this borrowed chord sound all by yourself. For example, maybe the guitars are playing an F5 power chord (F and C only) and the bass part hits an A then an A♭. Then the bass alone is creating this harmony.
Of course, be careful of applying this idea blindly. It can be a disaster if the other instruments aren't playing the same progression. Or, if you're composing the music, you don't have to shove this chord in-between every IV and I chord. Moderation!
Exercises and Song Examples
Again, if this lesson is a struggle for you, don't worry. You can return to it again in the future. The main lesson here is to expect to encounter non-diatonic chords mixed in with otherwise diatonic chords.